34. The triple point of CO₂ is at 5.2 atm and -57°C. Under atmospheric conditions present in a typical Boulder, Colorado, laboratory (P = 630 torr, T = 23° C), solid CO₂ will
(A) remain solid
(B) boil
(C) melt
(D) sublime
(E) none of these

30. In the molecular-orbital description of CO, (A) the highest energy electrons occupy antibonding orbitals (B) six molecular orbitals contain electrons (C) there are two unpaired electrons (D) the bond order is 3 (E) all of these are false

31. Which of the following is diamagnetic? (A) (B) (C) B2 (D) F2 (E) ВО

32. Which of the following statements is true? (A) electrons are never found in an antibonding MO (B) all antibonding MOs are higher in energy than the atomic orbitals of which they are composed (C) antibonding MOs have electron density mainly outside the space between the two nuclei (D) none of these statements is true (E) two of these statements are true

33. Based on intermolecular forces, which of the following will have the highest boiling point? (A) PF5 (B) SF4 (C) AsF5 (D) more information is needed to answer the question (E) all are liquids

35. A crystal of NaCl is (A) soft, low-melting, and a good electrical conductor (B) hard, high-melting, and a good electrical conductor (C) soft, low-melting, and a poor electrical conductor (D) hard, high-melting, and a poor electrical conductor (E) soft, high-melting, and a poor electrical conductor

36. The unit cell in a certain lattice consists of a cube formed by an anion at each corner, an anion in the center, and a cation at the center of each face. The unit cell contains a net (A) 5 anions and 6 cations (B) 5 anions and 3 cations (C) 2 anions and 3 cations (D) 3 anions and 4 cations (E) 2 anions and 2 cations

37. How many unpaired electrons are there in ? (A) 4 (B) 3 (C) 2 (D) 1 (E) 0

38. Which of the following statements is true of the crystal field model? (A) the interaction between metal ion and ligand is treated as a Lewis acid-base interaction (B) the ligands are treated as negative point charges (C) the metal ion-ligand bonds are considered completely ionic (D) the electrons are assumed to be localized (E) none of these statements is true

39. Which of the following statements about the complex ion is true? (A) the complex ion contains Co(I) (B) The complex ion exhibits cis and trans geometric isomers, but no optical isomers (C) the complex ion exhibits two geometric isomers (cis and trans) and two optical isomers (D) because en is a strong field ligand, the complex ion is paramagnetic (E) the geometric isomers of the complex ion have identical chemical properties

40. Which of the following is not a structural isomer of 1-pentene? (A) 2-pentene (B) 2-methyl-2-butene (C) cyclopentane (D) 3-methyl-1-butene (E) 1-methyl- cyclobutene